From: Matt Mackall <mpm@selenic.com>
This only checks in the non-__ versions, as those are occassionally
called inside things like kmap_atomic pairs which take a spinlock in
with highmem. It's all conditional on CONFIG_DEBUG_SPINLOCK_SLEEP
(which isn't quite the right name) so there's no overhead for normal
builds.
arch/i386/lib/usercopy.c | 3 +++
include/asm-i386/uaccess.h | 3 +++
2 files changed, 6 insertions(+)
diff -puN arch/i386/lib/usercopy.c~usercopy-might_sleep-checks arch/i386/lib/usercopy.c
--- 25/arch/i386/lib/usercopy.c~usercopy-might_sleep-checks 2003-08-02 12:08:25.000000000 -0700
+++ 25-akpm/arch/i386/lib/usercopy.c 2003-08-02 12:08:25.000000000 -0700
@@ -149,6 +149,7 @@ do { \
unsigned long
direct_clear_user(void __user *to, unsigned long n)
{
+ might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
__do_clear_user(to, n);
return n;
@@ -188,6 +189,8 @@ long direct_strnlen_user(const char __us
unsigned long mask = -__addr_ok(s);
unsigned long res, tmp;
+ might_sleep();
+
__asm__ __volatile__(
" testl %0, %0\n"
" jz 3f\n"
diff -puN include/asm-i386/uaccess.h~usercopy-might_sleep-checks include/asm-i386/uaccess.h
--- 25/include/asm-i386/uaccess.h~usercopy-might_sleep-checks 2003-08-02 12:08:25.000000000 -0700
+++ 25-akpm/include/asm-i386/uaccess.h 2003-08-02 12:08:25.000000000 -0700
@@ -299,6 +299,7 @@ extern void __put_user_bad(void);
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) *__pu_addr = (ptr); \
+ might_sleep(); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
__put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \
__pu_err; \
@@ -508,6 +509,7 @@ __direct_copy_from_user(void *to, const
static inline unsigned long
direct_copy_to_user(void __user *to, const void *from, unsigned long n)
{
+ might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
n = __direct_copy_to_user(to, from, n);
return n;
@@ -532,6 +534,7 @@ direct_copy_to_user(void __user *to, con
static inline unsigned long
direct_copy_from_user(void *to, const void __user *from, unsigned long n)
{
+ might_sleep();
if (access_ok(VERIFY_READ, from, n))
n = __direct_copy_from_user(to, from, n);
else
_